1. Field of the Invention
The present invention relates to a floating head support structure for an electric shaver in which the free articulated movement of the head portion in relation to the grip portion maintains improved contact between the shaving blades and the skin.
2. Description of Related Art
A conventional electric shaver of the type addressed by the invention incorporates a grip portion, a laterally pivotable head structured as a separate component from the grip portion, and a motor housed within the grip portion which is located beneath the head portion. This structure poses a problem in that it largely restricts the lateral swinging movement of the head portion, and thus limits the ability of the head portion to follow the contours of the skin.
Various types of conventional electric shavers are structured to allow movement of the head in relation to the grip as a means of better maintaining the cutting blades in contact with the skin during shaving. A typical example of this type of electric shaver places the motor in the head, and supports the pivoting movement of the head through front and rear walls built into the grip. This type of shaver is noted in Japanese Kokai Patent Publication No. H06-343776.
As noted by Japanese Kokai Patent Publication No. H06-343776, the motor and head are structured as a single unit which is supported by a front and rear wall, which are built into the grip, as a means of allowing the head to pivot in the lateral direction. The upper surface of the grip case must thus be constructed as an open structure that allows the motor to be housed therein, and further necessitates that the lower surface of the head be formed to the same radius as the open part of the grip case as a means of covering the grip case. This structure allows the head to move only on the radial surface provided, thus limiting the range of movement of the head in relation to the grip, and thus preventing the head from moving in a way that could more accurately follow the contours of the skin being shaved. Furthermore, the grip case must be made to a relatively large width, that is, a width greater than that of the head, to allow sufficient space for the movement of the motor which must laterally swing with the head, thus necessitating a grip that is difficult to size for a comfortable fit to the hand.
Another example of a conventional electric shaver of the type relating to the invention is one in which the motor and head are incorporated as a single structure capable of a laterally rotating and telescoping movement against the skin. Accordingly, this type of electric shaver incorporates a head support structure that allows both a lateral pivoting and telescopic movement of the head as noted in Japanese Kokai Patent Publication No. H10-43443.
As the electric shaver noted in Japanese Kokai Patent Publication No. H10-43443 also describes a structure in which the motor part of the integrated head/motor unit extends into the grip, the head is still not able to pivot to an adequate angle in the lateral direction due to the motor contacting the limiting inner surfaces of the grip case.
Moreover, a rotational support structure has been put forth in WO 00/38891, for example, for an electric shaver head that contains both the shaving blades and motor within the head case, and that supports the fore-aft pivoting movement of the head on a shaft located near the top of the head. In this structure, the pivoting movement of the head results in the lower part of the head potentially swinging to a point that exceeds the boundary of the grip. The head must thus be made to relatively small dimensions to prevent the lower part from coming into contact with the user's fingers holding the grip, thus necessitating that a correspondingly small motor be employed with the result that the electric shaver provides relatively weak shaving power. A structure could be considered in which the location of the shaft on which the head rotates is lowered, but this could result, depending on the attitude of the shaver when held by the user, in the head freely rotating when separated from the skin, and thereby preventing the shaver from providing an adequate level of performance.